diff --git a/keyboards/helix/rev2/matrix.c b/keyboards/helix/rev2/custom/matrix.c
similarity index 100%
rename from keyboards/helix/rev2/matrix.c
rename to keyboards/helix/rev2/custom/matrix.c
diff --git a/keyboards/helix/rev2/split_scomm.c b/keyboards/helix/rev2/custom/split_scomm.c
similarity index 100%
rename from keyboards/helix/rev2/split_scomm.c
rename to keyboards/helix/rev2/custom/split_scomm.c
diff --git a/keyboards/helix/rev2/split_scomm.h b/keyboards/helix/rev2/custom/split_scomm.h
similarity index 100%
rename from keyboards/helix/rev2/split_scomm.h
rename to keyboards/helix/rev2/custom/split_scomm.h
diff --git a/keyboards/helix/rev2/split_util.c b/keyboards/helix/rev2/custom/split_util.c
similarity index 100%
rename from keyboards/helix/rev2/split_util.c
rename to keyboards/helix/rev2/custom/split_util.c
diff --git a/keyboards/helix/rev2/split_util.h b/keyboards/helix/rev2/custom/split_util.h
similarity index 69%
rename from keyboards/helix/rev2/split_util.h
rename to keyboards/helix/rev2/custom/split_util.h
index 535949118a7..3b1d4249f55 100644
--- a/keyboards/helix/rev2/split_util.h
+++ b/keyboards/helix/rev2/custom/split_util.h
@@ -1,5 +1,10 @@
 #pragma once
 
+#ifdef SPLIT_KEYBOARD
+#   error This is helix local split_util.h.
+#   error This header file is used only when SPLIT_KEYBOARD=no.
+#endif
+
 #include <stdbool.h>
 #include "eeconfig.h"
 
@@ -14,7 +19,3 @@ void split_keyboard_setup(void);
 bool is_helix_master(void);
 
 void matrix_master_OLED_init (void);
-
-// stubs as this is handled by legacy code
-static inline void split_pre_init(void){}
-static inline void split_post_init(void){}
diff --git a/keyboards/helix/rev2/local_features.mk b/keyboards/helix/rev2/local_features.mk
index cfff8fd64d5..c6f818bf397 100644
--- a/keyboards/helix/rev2/local_features.mk
+++ b/keyboards/helix/rev2/local_features.mk
@@ -52,9 +52,10 @@ ifneq ($(strip $(SPLIT_KEYBOARD)), yes)
 
   CUSTOM_MATRIX = yes
 
-  SRC += rev2/matrix.c
-  SRC += rev2/split_util.c
-  SRC += rev2/split_scomm.c
+  SRC += rev2/custom/matrix.c
+  SRC += rev2/custom/split_util.c
+  SRC += rev2/custom/split_scomm.c
+  KEYBOARD_PATHS += $(HELIX_TOP_DIR)/rev2/custom
 endif
 
 ########